@rem:77rem;
*{
  margin: 0;
  padding: 0;
}
li{
  list-style: none;
}
section{
  height:300/@rem;
  border:1px solid blue;
}
section ul{
  display: -webkit-flex;
  display: flex;
}
section ul li{
  //width: 20%;
  //float: left;
  //box-sizing: border-box;
  flex: 1;
}
section ul li a{
  display: block;
  height: 100%;
  border:1px solid red;
  text-align: center;
}
section ul li a span{
  font-size: 30/@rem;
}